Bending machine



July 12, 1966 R. M. SHAW, JR 3,260,091

BENDING MACHINE Filed May 24, 1963 6 Sheets-Sheet 1 INVENTOR.

July 12, 1966 R. M. SHAW, JR 3,260,091

BENDING MACHINE Filed May 24, 1965 6 Sheets-Sheet 2 IN VEN TOR.

R. M. SHAW, JR

BENDING MACHINE July 12, 1966 6 Sheets-Sheet 5 Filed May 24, 1963 Q R QQ INVENTOR. fiayfi/H 5176b, BY

J2 wigz y 1966 R. M. SHAW, JR 3, 60,091

BENDING MACHINE Filed May 24, 1963 6 Sheets-Sheet 4 FIG: 4

IN VEN TOR.

July 12, 1966 R. M. SHAW, JR

BENDING MACHINE 6 Sheets-Sheet 5 Filed May 24, 1965 INVENTOR. Ali/p];MSM JI: BY

United States, Patent 3,260,091 BENDING MACHINE Ralph M. Shaw, Jr.,Edgewater Parlc, N.J., assignor to Pedrick Tool and Machine Company,Inc., Philadelphia, Pa., a corporation of Pennsylvania Filed May 24,1963, Ser. No. 283,021 13 Claims. (Cl. 72152) This invention relates tobending machines and, in particular, it is concerned with machines andimprovements thereto for angularly bending rods, bars, tubes and thelike of metal or other flexible materials.

It is the primary object of this invention to provide a simple,inexpensive and reliable bending machine for making profile bends ofvariable radii or multiple radii in stock with the bending occurring ineither a clockwise or counter-clockwise direction in a single operationor pass of the machine. Although an existing machine known as a StretchBender can do this type of bending, all of the bends produced by thatmachine can only be made in the same direction and the machine itself,as distinguished from the machine of this invention, is extremelyexpensive.

It is a further object of this invention to provide a bending machinehaving the capacity to implant bends in structural members which havebeen traditionally shaped by drop forging through use of a punch presswhile the members are hot, thus providing substantial savings in timeand costs.

It is a further object of this invention to provide a bending machinehaving, in addition to the above outlined advantages, the featurewherein relatively large floor space heretofore necessary to accommodatemove ment of the bending stock and bending apparatus is no longerrequired. It is also my object to provide a superior bending apparatuswhich can be assembled and used with the standard bending machines nowin existence, such as the mechanism described in US. Patent No.2,884,987, issued to R. M. Shaw, Jr., on May 5, 1959.

Other objects and attendant advantages of this invention will morereadily appear from the following detailed description and the attacheddrawings wherein:

FIG. 1 is a view in top plan of the bending machine convenientlyembodying one form of my invention;

FIG. 2 is a view in side elevation of the mechanism shown in FIG. 1;

FIG. 3 is a view in partial side elevation and in vertical section takenas indicated by the lines and arrows III-III in FIG. 1;

FIG. 4 is a view in top plan illustrating the movement of certain partsof the apparatus from the positions shown in FIG. 1;

FIG. 5 is a fragmentary detail plan view of one modification of thebending apparatus of this invention;

FIG. 6 is a fragmentary detail plan view similar to FIG. 5 wherein asucceeding operative step is shown;

FIG. 7 is a fragmentary detail plan view showing the third step of thebending operation wherein a chain link is formed;

FIG. 8 is a fragmentary detail plan view showing the fourth step of thebending operation otherwise disclosed in the preceding three figures;

FIG. 9 is a vertical sectional view taken along the lines and arrowsIX-IX of FIG. 5;

FIG. 10 is a vertical sectional view taken along the lines and arrows XXof FIG. 5;

FIG. 11 is an enlarged perspective view of the bent stock having aU-shape; and,

FIG. 12 is an enlarged perspective view of the finished bent stockforming a closed chain link.

Although this description makes use of the technical words of the art,it will be understood that the invention is not limited to the apparatusdescribed thereby and that equivalent structure and substitutions may bemade where such are practical and advantageous.

It should be understood that the mechanism of this invention and themethod of operation thereof constitutes an appreciable improvement tothe basic bending machines well known in the art whereby saidinexpensive machines gain capacity to create shapes heretoforeunattainable. For example, the machine disclosed in my United StatesPatent No. 2,884,987, dated May 5, 1959, is representative of a suitablebending machine to which the improvements of this invention can beeffectively applied and incorporated. The description of the bendingmachine set forth in that patent is included herein by reference andcertain mechanical apparatus fully disclosed in that patent are onlygenerally described in this application.

Referring, preliminarily, to FIG. 2, of the drawings, a typical bendingmachine is shown comprising a table like work base 10 supported at aworking height from the fioor brace 14 by a plurality of legs 12, Thelegs and table define an interior area 13 wherein the drive apparatus,generally designated by the numeral 15, of the machine is located. Thedrive apparatus 15 comprises a reversible electric motor 16 connected toa drive shaft 30 by a pair of meshing beveled gears 19 and 20. Shaft 30has a spur gear 34 fixedly mounted thereon, gear 34 being engaged with asecond spur gear 36 fixedly mounted on a spindle sleeve 40a. The meshingspur gears 34 and 36 are of such relative size that spindle sleeve 40ais driven at approximately one half the speed of shaft 30. It should beunderstood that the drive mechanism disclosed herein is but one form ofvarious types of drive apparatus which can be used to rotate shaft 30and spindle sleeve 40a at pre-determined rates of speed, in bothdirections, according to the manipulation of control switches (notshown) by an operator. A speed reducer can be included in the drivemechanism if necessary.

Positioned immediately on top of base 10 and rotating freely thereabove,is a flat, circular shaped supporting member or plate 60. Plate has thesame axis as does spindle sleeve 4011 even though the members rotateseparately. Fixedly mounted on member 60 is a single, wiper armassembly, generally designated by the numeral 64. Spindle 40, acontinuation of spindle sleeve 40a, extends above plate 60 and rotatesseparately from base member of the stationary wiper arm assembly 72shown in FIG. 1. A piece of rod stock S is shown in position against aninterchangeable die 74 which is held in position by a threaded nut 75.

Referring now to FIG. 1 of the drawings, it is seen that circular table10 is larger in diameter than moveable plate 60, and that the rnoveablewiper arm assembly 64 is fixedly attached to the plate 60 by bolts 65,only one being shown in FIG. 1. In distinction, stationary wiper armassembly 72 is fixably attached to table 10 by two bolts 72a.

The moveable wiper arm assembly 64 comprises a wiper arm 62 having acenter slot '63 in which a slide 61 (shown in FIG. 3) moves. Atapered-end swaging block 66 is mounted on slide 61 by a pair ofthreaded bolts 68. A threaded stem 67, attached to slide 61 and threadedthrough block 67a in arm 62 allows the swaging block 66 to be adjustedcloser or at a greater distance from the tube or bar stock S.

The stationary wiper arm assembly 72 is similar in construction toassembly 64 and consists of an arm 75 having a base 70 extending aroundspindle 40, a central groove 76, a swaging block 78 mounted on a slide(not shown) by a pair of bolts 80, the slide controlled by a stem 73operating through a block 7311. 1

An interchangeable, work piece clamp assembly 84 is attached to thespindle 40 by a member 86 which extends around spindle 40 and holds theassembly 84 tightly thereagainst. Base member 85 of the clamp 84 has anupstanding stud 87 with a threaded bore 88 extending through the center.A bearing block 90 presses against the stock S and is held by a threadedshaft 92 extending through bore 88 and a knurled thumb adjusting surface94. The bearing block 90 can be adjusted by threading the shaft 92 so asto move the block at a greater or'less distance from the die 74 heldopposite at the top of the spindle 40.

Referring now to FIG. 3 of the drawings, it is seen that most of thestructure shown and described in connection with FIGS. 1 and 2 is shownin this figure in vertical sectional view. Spindle sleeve 40a extendsupward through a hole 11 in the table 10 where it joins spindle 40. Gear36, keyed at point 35, delivers torque from the spur gear 34 and shaft30 to spindle 40 which, in turn, is keyed at point 4-2 to a center plug44. Positioned on top of plug 44 is an interchangeable die 74 which isselected according to the shape of the stock and the desired angle orbend to be implanted. A pair of locking pins 45 maintain die 74 rigidwith plug 44 and bolt 75 is threaded into plug 44 to complete theengagement. Clamp base 86, mounted around plug 44, is held tightlyagainst that element by a plurality of threaded plugs 86a one of whichis shown in FIG. 3. Within a recessed area 102 in table 10, a spur gear81 is mounted on shaft 30, this gear engages a second spur gear 82 whichrotates freely around the base of spindle 40. A plurality of threadedbolts 83, two of which are shown in FIG. 3, fixedly connect gear 82 tothe moveable plate 60. It should be understood that the torque suppliedby motor 16 through shafts 24 and 30 is delivered to spindle 40 by gears34 and 36, and, at the same time, torque is also delivered to moveablesupport plate 60 by means of gears 81 and 82.

The operation of this form of my invention is sub stantially as follows.The selected bar or tube stock S is placed against a selected die 74 andthe bearing block 90 of the clamp assembly 84 is threaded tight pressingthe stock S firmly against the die. Wiper arm assemblies 64 and 72 areplaced in the initial position, that is, adjacent one another, as inFIG. 1 and the swaging blocks 66 and 78 are positioned in contact withthe stock When motor 16 is started and torque delivered through thegears, the wiper arm assembly 64, attached to moveable plate 60, beginsto rotate in a clockwise direction as seen in FIG. 1, while wiperassembly 72 remains stationary. Accordingly, spindle 40, die 74 andclamp assembly 84 begin to rotate in the same direction as torque isdelivered to gear 36. Referring now to FIG. 4, it will be observed thatmoveable wiper assembly 64 has rotated approximately 180 degrees whilethe spindle has rotated approximately 90 degrees, and, as a consequence,the stock S and, particularly, its ends S-1, 5-2 have been bent arounddie 74 into a U-shape. Stock S is held tightly against the die member atall times by the clamping assembly 84 so that no movement of the stockseparate from the die is permitted. During normal operations, power iscontinually applied until wiper arm 64 rotates beyond the 180 degreeposition so that the ends S1, 5-2

almost touch. At this point, the motor is reversed by a limit switch(not shown) and the wiper apparatus 64 and plate 60 rotate back to theposition shown in FIG. 1. The clamp 84 and the swaging blocks 66, 78 arethen loosened so that the stock S can be removed, It has been found thatwhen the stock 5 is composed of a flexible material it is oftenadvisable to bend the stock beyond the U-shape position so that when itis removed from the bending machine, the bent stock will spring only toa U-sha-pe. It should be understood that this apparatus can besupplemented with a series of switches and electrical circuits asdisclosed in Patent No. 2,884,- 987, referred to above, whereby themachine operation is partially automatic. Automatic switches can beplaced on table 10 so that forward direction of the wiper apparatus 64is stopped before the ends S1, S2 of the stock come into contact.

A modification of the bending machine of this invention is illustratedin FIGS. 5 through 8. Referring first to FIG. 5, a stationary wiper arm91 is fixedly mounted to the table 10 and moveable armb 93 is mounted tomoveable support plate 60. In describing these figures, parts having thesame construction and operation as in the preceding figures will beidentified by the same numbers. Mounted for movement around upstandingstuds 95 and 99 of arms 91 and 93 are swaging blocks 96 and 98,respectively, each having an indentation 96a and 98a at the inner end.The spindle 40 and plug 44, driven in a manner similar to that disclosedin FIG. 3, is equipped with an elliptical cross-piece member 102 whichis attached to plug 44 by a bolt. 112, member 102 forming the base forthe clamp assembly 84. A pair of round dies 104 have cylindrical bases104a extending through a pair of bearing members 106, 108. Thesemembers, at the end, have raised elongated portions 106a and 108a whichbear against the stock S as described below.

Referring now to FIG. 9, spindle 40 is shown having a plug 44 with a key42 connecting the two, and a bolt 112 holding the clamping base 102 tothe plug 44. It should be understood that when spindle 40 rotates thedies 104 together with hearing members 106, 108, rotate holding thestock S in the position shown.

As shown in FIG. 10, swaging stud 95 extends upward from wiper arm 91through the swaging block 96 and allows said member to rotatetherearound.

The operation of this modification of this invention, designed primarilyto form chain links out of tubular stock, is described below. In FIG. 5,the stock S is positioned between the two dies 104 and the clampapparatus 84. The stock S is also held between the hearing members 106,108 and the two dies 104, and the members 106, 108 fitting withinrecesses 96a and 98a of the swaging blocks. After the clamp 84 isthreaded tightly against the stock S, the motor is started therebymoving plate 60 and wiper arm 93 in a clockwise direction until, asshown in FIG. 6, the swaging blocks 96 and 98 have bent the stock S intosubstantially a U-shape. As shown in FIG. 7, the motor is then reversedand the moveable wiper arm 93 is returned almost to the initialposition. Then swaging blocks 96 and 98 are rotated around plugs 95 and99, as shown by the dot and dash lines so that the raised portions 106aand 108a of hearing members 106, 108 can be positioned outside of theswaging blocks 96 and 98 as shown in FIG. 7, after which blocks 96 and98 are returned to the full line portions shown. With the bearingmembers 106a and 108a now pressed against the ends S-1 and S-2, and theswaging blocks 96 and 98 pressed against the bearing members, the motoris activated in the forward direction causing the bearing members 106,108 to close the ends of the stock so as to form a complete link asshown in FIG. 8. In FIGS. 11 and 12, the tubular stock S is shown havinga U-shape and then as a closed link.

It should be understood that although the apparatus of this inventionhas been described as bending simple bar stock into U-bolts and closedlinks, the same apparatus with suitable stationary and moveable dies canbe used to bend in one operation unusual shapes, such as the roof trussof a railroad car. The roof truss of a bus customarily has a long sweepin the middle and a straight bend on each end. These structural membersare normally made on a punch press and are bent while hot by what isknown as drop forging. The same bending can be achieved by the machineof this invention saving the very considerable costs of a heatingfurnace, a drop forge, the punch press and the dies together with thenecessary labor. In addition, my bending machine is adaptable to formingin one operation the side frames of a glider having multiple bends ofclose radii while comparative machines require two or more passes toimplant similar bends in such stock.

Although this invention has been described with reference to specificforms and embodiments thereof, it will be apparent to those skilled inthe art that various changes other than those referred to above may bemade in the form of the apparatus, that equivalent elements may besubstituted for those illustrated in the drawings, that parts may bereversed, and that certain features of the invention may be used toadvantage independently of the use of other features, or within thespirit and scope of the invention as defined in the appended claims.

Having described my invention; I claim:

1. In a bending machine, the combination comprising a spindle mountedfor rotation, a die mounted on the spindle for movement therewith, anadjustable clamp fixedly attached to the spindle and positioned to holdthe work against the die as the spindle rotates, a moveable supportplate mounted coaxially with the spindle but arranged to rotate freelytherefrom, a moveable bending arm fixedly mounted on said support meansproximate to the spindle so that upon rotation of the support means thebearing surface of the bending arm describes an arc around the spindle,a stationary bending arm fixedly mounted adjacent the spindle andpositioned so that when the spindle rotates the bearing surface ofthestationary bending arm describes an are around the spindle identical tothat of the moveable bearing arm, a power source and a gear trainconnecting the source to both the spindle and the support means, saidgear train being arranged so that the spindle and support means rotatein the same direction with the support means rotating at twice thevelocity of the spindle.

2. The bending machine as defined in claim 1 wherein the clamp comprisesa clamp base mounted on the spindle, a threaded bearing arm having abearing block at the end proximate to the die and a threaded bore studmounted on the clamp base through which the bearing arm is adjusted soas to press the bearing block against the stock.

3. The bending machine as defined in claim 2 wherein the support platerotates around the spindle, the plate being attached to a :spur geartherebeneath which rotates around the spindle, said spur gear beingdniven by a second gear mounted on a driving shaft.

4. In a bending machine, the combination comprising a flat supporttable, a spindle positioned on the table and mounted for rotation, a diefixedly mounted on the spindle for rotation therewith, an adjustableclamp fixedly attached to the spindle and positioned to hold the work tobe bent against the die as the spindle rotates, a moveable support platemounted coaxially with the spindle and in the same plane as the tablesoas to rotate freely thereon, a moveable wiper assembly fixedly mountedon said support plate proximate to the spindle so that upon rotation ofthe support plate the bearing surface of the wiper assembly describes anare around the spindle, a stationary wiper assembly fixedly mounted onthe table adjacent the spindle and positioned relative to the spindle sothat when the spindle rotates the leading edge of the stationary rwiperarm describes an arc identical with that of the moveable wiper arm, bothof said wiper arms being positioned adjacent one another at the initialstep of the bending operation, a power source and a gear trainconnecting the source to the spindle and the support means, said geartrain arranged to rotate the spindle and support plate in the samedirection while the support plate rotates at twice the velocity of thespindle.

5. The bending machine .as defined in claim 4 wherein a pair of bearingmembers are mounted on the spindle and rotate therewith, said membersbeing shaped to hold the work and being positioned so that the wiperarms press against the members and cause the work to be bent completelyaround the spindle.

6. In a machine of the character described, for bending rods, bars,tubes and the like, the combination comprising revolva-ble die means, astationary main bending member, a movable main bending member, saidbending members being disposed for engaging one side of the workrespectively at longitudinally spaced points along the length thereof,said die means being disposed for engaging the opposite side of the workat a point intermediate the points engaged by said bending members,means mounting said movable bending member for descnibing an are aboutsaid die means, a power source, gear means operatively interposedbetween said power source and both said die means and movable bendingmember and operable for actuating said die means and simultaneouslymoving said movable bending member at a substantially greater angularrate than that at which said die means is turned.

7. The bending machine according to claim 6 wherein a clamp operable forsecuring the work to the die means is mounted for rotary movement withthe die means.

8. The bending machine according to claim 6 wherein the angular rate ofmovement of the movable bending member is twice as great as that of thedie means.

9. The bending machine according to claim 6 wherein auxiliary bendingmembers are operable for bending the opposite end portions of the workrespectively about said die means, and said main bending members areoperable independently of said auxiliary bending members for bending theopposite end portions of the 'work approximately ninety degreesrespectively about said die means, and for then actuating said auxiliarybending members whereby to bend the opposite end portions of the workapproximately another ninety degrees respectively about said diemembers.

10. The bending machine according to claim 9 where in the die means isprovided with oppositely facing rounded surface areas about which,respectively, the opposite end portions of the work are bent, and theauxil'ia-ry bending members are mounted for pivotal movementrespectively about the centers of curvature of said surface areas.

11. The bending machine according to claim 9 wherein the die meansincludes a pair of members round in transverse section disposed onopposite sides of, and equidistantly from, the central axis of themachine and mounted for orbital movement about said axis, and theauxiliary bending members are mounted for pivotal movement respectivelyabout said pair of members.

'12. The bending machine according to claim 9 wherein the main bend-ingmembers respectively include pivotally mounted work engaging parts, andthe auxiliary bending members and said work engaging parts areselectively operatively positionable with said auxiliary bending membersbetween said work engaging parts or with said work engaging partsbetween said auxiliary bending members.

13. In a machine of the character described, for bending rods, bars,tubes and the like, the combination comprising a rotatable support, aspindle extending through said support and rotatable independentlythereof, a die, clamping means for holding the work against the dieduring the bending operation, said die and clamping means being mountedon said spindle for'rotating therewith, a stationary bending membermounted adjacent the die, a movable bending member mounted upon saidrotatable support adjacent the stationary bending member for describingan are around the die, each of said bending members including an armhaving a central lengthwise groove, a slide adjustably positioned withinthe groove, and a swaging block mounted upon said slide, a power source,and connecting means arranged between the power source and both the dieand the movable bending member independently whereby in the bendingoperation both the die and the movable bending member rotate in the samedirection, the bending member rotating faster than the die.

References Cited by the Examiner UNITED STATES PATENTS 670,0'19 3/1901Gillies 72--400 2,501,241 3/1950 Shaw 72155 2,884,987 5/1959 Shaw 72-3830 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

1. IN A BENDING MACHINE, THE COMBINATION COMPRISING A SPINDLE MOUNTEDFOR ROTATION, A DIE MOUNTED ON THE SPINDLE FOR MOVEMENT THEREWITH, ANADJUSTABLE CLAMP FIXEDLY ATTACHED TO THE SPINDLE AND POSITIONED TO HOLDTHE WORK AGAINST THE DIE AS THE SPINDLE ROTATES, A MOVEABLE SUPPORTPLATE MOUNTED COAXIALLY WITH THE SPINDLE BUT ARRANGED TO ROTATE FREELYTHEREFROM, A MOVEABLE BENDING ARM FIXEDLY MOUNTED ON SAID SUPPORT MEANSPROXIMATE TO THE SPINDLE SO THAT UPON ROTATION OF THE SUPPORT MEANS THEBEARING SURFACE OF THE BENDING ARM DESCRIBES AN ARC AROUND THE SPINDLE,A STATIONARY BENDING ARM FIXEDLY MOUNTED ADJACENT THE SPINDLE ANDPOSITIONED SO THAT WHEN AND A GEAR TRAIN CONNECTING THE SOURCE TO BOTHTHE SPINDLE THE SPINDLE ROTATES THE BEARING SURFACE OF THE STATIONARYBENDING ARM DESCRIBES AN ARC AROUND THE SPINDLE IDENTICAL TO THAT OF THEMOVEABLE BEARING ARM, A POWER SOURCE AND THE SUPPORT MEANS, SAID GEARTRAIN BEING ARRANGED SO